Commercial building services / Practical guide
Commercial Ventilation Maintenance and Indoor Air Quality
An air-handling or ventilation brief should describe the system, building use and findings, rather than assume that every air-quality concern has the same cause.
Reviewed and rewritten 12 October 2026. General planning guidance; agree the actual technical scope for your building.
Identify the system
List AHUs, fans, ductwork, filters, controls and the areas served, where this information is available. Explain the building use and changes in occupancy or layout. Existing drawings and maintenance records help define the starting point.
Describe the actual concern
Report comfort, airflow, noise, odour or operating issues and where they occur. These symptoms can have different causes. Avoid using a maintenance visit as a substitute for any separate specialist assessment that the situation requires.
Agree maintenance and access
Define the equipment and tasks, the access needed and any restrictions on working in the building. Check the relevant manufacturer information and authorised schedules where specified. Make responsibility for related specialist systems and inspections explicit.
Keep reports connected
A useful record identifies what was inspected or maintained, limitations, findings and recommended actions. Keep ventilation work connected to the related controls and heating or cooling requirements without losing the boundaries of the agreed scope.
Use evidence to plan changes
Recurring faults or changes in building use may call for investigation, controls work or a replacement project. Define the required outcome and the design responsibility before changing the system. Claims about health or energy outcomes need evidence; this guide makes no guaranteed outcome claim.
Turn the information into a useful enquiry
Include the site postcode, the systems and the work required. Add records, symptoms and access restrictions where relevant. For urgent faults, call to discuss availability.